Method of determining frequency of periodic impulses.



APPLICATION FILED JUNE 12. "09v Patented Apr. 94 1912.

R Q T N E V N UNITED STATES I I REGINALD A. FESSENDEN, F BRANT BOGK, MASSACHUSETTS/ASSIGNOR 'IO NATIONAL ELECTRIC SIGNALING COMPAN "OF-PITTSBURGH, PENNSYLVANIA, A CORPORA- TION OF NEW JERSEY.

METHOD or DETERMINING rnnounnor or rnalonic iivrrunsns.

Specification of Letters Patent.

1903, Serial NO. 164,738t

Patented Apr. 9, 1912. Divided and this application filed June 12,

To all w/wm at may concern:

Be it known that LREGINALI) A. Fnssnn- DEN, a citizen of. the United States, res1d ing at Brant Rock, -Pl'ymouth county, State of Massachusetts, have invented a certain. new and useful Method of Determining Frequency of Periodic Impulses, of which the following is a specifica'tio1i.

1 My invention relates, to the measurement 1-0 of the electrical constants of electric circuits fland more particularly to electro-magnetic qgwave measurements,- this, application/being 1 'af division of ,my application No. 164,738, mxfiled July 8th, 1903.

" part of this specification "shows in diagram The accompanying drawing forming, a

an arrangement suitable for carrying out the invention. i

The inventionhas for its object the measurementof the electric constants of electrical apparatus and electrical "circuits. It is cshrough the \primaries 34," 36\t0 the ground 55.

1 j 37, 40, 4c; 38', 41,47, 39, 42, 48 cuits operatively connected to the primaries cir- 34', 35, 36 respectively. o, i The circuit 44, 50, 57, 82, 81 is placed inductive relation to the 'circuit'which it desired to measure, 44 being aninductance,f

a capacity, 81. a variable'inductance, 82 a variable condenser, 57 a'reoeiver, preferablyof the current opera-ted type, a pot tentiometer, 54 a battery, 52 an indicating instrument.

For tuning condu'ctors I"prefer:to. use" the hot wire receiver described in U. S.- Patent No. 7 06,742, shown at 57, and to use ance shown at 81' consisting of two cylinders one of hard rubber and the other, 81 of electrolytic copper. "The cylinder of electrolytic copper 81 acts as. a closed secondary anclhetptralizesihe self inductionof all the 52 as the indicating instrument while tuning instead of a telephone. A variable capacity 82 may also be used in conjunction with an inductance, such as 44, by opening theswitch 83 and closing the switch 84,-and in some respects is preferable to it as thebspacity of the varying inductance also varies somewhat with the inductance while the inductance of the varying capacity is practically constant.

In order to determine the tune of a circuit correctly, for example the circuit, 38, 41, 47 it is found advisable to insert dampening resistances shown at 80, 80, 8O inall circuits except theone which it is desired/ to measure, 6. e., except in 38, 41, 47v as other'- wise the oscillations set up in the otheiycircuits will affect the periodicity'of one being measured. 1

In the practice of my inventidnthe galvanometer 52 gives a maximum indication/ 82, 81 has the when the circuit 44, 50, 57: samezfrequency adthatoft ecircuit 38, ,4'1,

47 and, the inductaiices and capacities of this circuitifbeing known the frequencyof the circuit 41, 47 is thus determined. It-is preferred to have /separate ,tuning coil capable ofdifeing v ried inseriesiwith the *vertical at the poi t, 63. f-

Having thitsqdescribed my invention and illustrated its rise, what I claim as new and pan-e to secure Letters Patent, is the folowiii method offi determining the period of ought severalassociated oscillating 'cir-' cuits, which consists dampening the 0scilin connectigp therewith' a variable induct j jlations intall but onaof said circuits and bringing into resonance with that one an In testimony whereof I have hereundei.

inductively connected auxiliary circuit havsigned my name in the presence of the two ing electrical constants variable 111 known SUbSCllbd wltnesses.

degreeywhereby the auxiliary circuit is by REGINALD A. FESSENEDEN. known adjustment brought to the same W'itnesseszknown periodicity as the circuit to be meas- JESSIE BENT,

ured.

FLORENCE M. LYON. 

